//download.js v4.2, by dandavis; 2008-2016. [CCBY2] see http://danml.com/download.html for tests/usage
// v1 landed a FF+Chrome compat way of downloading strings to local un-named files, upgraded to use a hidden frame and optional mime
// v2 added named files via a[download], msSaveBlob, IE (10+) support, and window.URL support for larger+faster saves than dataURLs
// v3 added dataURL and Blob Input, bind-toggle arity, and legacy dataURL fallback was improved with force-download mime and base64 support. 3.1 improved safari handling.
// v4 adds AMD/UMD, commonJS, and plain browser support
// v4.1 adds url download capability via solo URL argument (same domain/CORS only)
// v4.2 adds semantic variable names, long (over 2MB) dataURL support, and hidden by default temp anchors
// https://github.com/rndme/download

(function (root, factory) {
  if (typeof define === 'function' && define.amd) {
    // AMD. Register as an anonymous module.
    define([], factory);
  } else if (typeof exports === 'object') {
    // Node. Does not work with strict CommonJS, but
    // only CommonJS-like environments that support module.exports,
    // like Node.
    module.exports = factory();
  } else {
    // Browser globals (root is window)
    root.download = factory();
  }
}(this, function () {

  return function download(data, strFileName, strMimeType) {

    var self = window, // this script is only for browsers anyway...
      defaultMime = "application/octet-stream", // this default mime also triggers iframe downloads
      mimeType = strMimeType || defaultMime,
      payload = data,
      url = !strFileName && !strMimeType && payload,
      anchor = document.createElement("a"),
      toString = function(a){return String(a);},
      myBlob = (self.Blob || self.MozBlob || self.WebKitBlob || toString),
      fileName = strFileName || "download",
      blob,
      reader;
    myBlob= myBlob.call ? myBlob.bind(self) : Blob ;

    if(String(this)==="true"){ //reverse arguments, allowing download.bind(true, "text/xml", "export.xml") to act as a callback
      payload=[payload, mimeType];
      mimeType=payload[0];
      payload=payload[1];
    }


    if(url && url.length< 2048){ // if no filename and no mime, assume a url was passed as the only argument
      fileName = url.split("/").pop().split("?")[0];
      anchor.href = url; // assign href prop to temp anchor
      if(anchor.href.indexOf(url) !== -1){ // if the browser determines that it's a potentially valid url path:
        var ajax=new XMLHttpRequest();
        ajax.open( "GET", url, true);
        ajax.responseType = 'blob';
        ajax.onload= function(e){
          download(e.target.response, fileName, defaultMime);
        };
        setTimeout(function(){ ajax.send();}, 0); // allows setting custom ajax headers using the return:
        return ajax;
      } // end if valid url?
    } // end if url?


    //go ahead and download dataURLs right away
    if(/^data\:[\w+\-]+\/[\w+\-]+[,;]/.test(payload)){

      if(payload.length > (1024*1024*1.999) && myBlob !== toString ){
        payload=dataUrlToBlob(payload);
        mimeType=payload.type || defaultMime;
      }else{
        return navigator.msSaveBlob ?  // IE10 can't do a[download], only Blobs:
          navigator.msSaveBlob(dataUrlToBlob(payload), fileName) :
          saver(payload) ; // everyone else can save dataURLs un-processed
      }

    }//end if dataURL passed?

    blob = payload instanceof myBlob ?
      payload :
      new myBlob([payload], {type: mimeType}) ;


    function dataUrlToBlob(strUrl) {
      var parts= strUrl.split(/[:;,]/),
        type= parts[1],
        decoder= parts[2] == "base64" ? atob : decodeURIComponent,
        binData= decoder( parts.pop() ),
        mx= binData.length,
        i= 0,
        uiArr= new Uint8Array(mx);

      for(i;i<mx;++i) uiArr[i]= binData.charCodeAt(i);

      return new myBlob([uiArr], {type: type});
    }

    function saver(url, winMode){

      if ('download' in anchor) { //html5 A[download]
        anchor.href = url;
        anchor.setAttribute("download", fileName);
        anchor.className = "download-js-link";
        anchor.innerHTML = "downloading...";
        anchor.style.display = "none";
        document.body.appendChild(anchor);
        setTimeout(function() {
          anchor.click();
          document.body.removeChild(anchor);
          if(winMode===true){setTimeout(function(){ self.URL.revokeObjectURL(anchor.href);}, 250 );}
        }, 66);
        return true;
      }

      // handle non-a[download] safari as best we can:
      if(/(Version)\/(\d+)\.(\d+)(?:\.(\d+))?.*Safari\//.test(navigator.userAgent)) {
        url=url.replace(/^data:([\w\/\-\+]+)/, defaultMime);
        if(!window.open(url)){ // popup blocked, offer direct download:
          if(confirm("Displaying New Document\n\nUse Save As... to download, then click back to return to this page.")){ location.href=url; }
        }
        return true;
      }

      //do iframe dataURL download (old ch+FF):
      var f = document.createElement("iframe");
      document.body.appendChild(f);

      if(!winMode){ // force a mime that will download:
        url="data:"+url.replace(/^data:([\w\/\-\+]+)/, defaultMime);
      }
      f.src=url;
      setTimeout(function(){ document.body.removeChild(f); }, 333);

    }//end saver




    if (navigator.msSaveBlob) { // IE10+ : (has Blob, but not a[download] or URL)
      return navigator.msSaveBlob(blob, fileName);
    }

    if(self.URL){ // simple fast and modern way using Blob and URL:
      saver(self.URL.createObjectURL(blob), true);
    }else{
      // handle non-Blob()+non-URL browsers:
      if(typeof blob === "string" || blob.constructor===toString ){
        try{
          return saver( "data:" +  mimeType   + ";base64,"  +  self.btoa(blob)  );
        }catch(y){
          return saver( "data:" +  mimeType   + "," + encodeURIComponent(blob)  );
        }
      }

      // Blob but not URL support:
      reader=new FileReader();
      reader.onload=function(e){
        saver(this.result);
      };
      reader.readAsDataURL(blob);
    }
    return true;
  }; /* end download() */
}));
